Improvements in toothbrushes for personal hygiene purposes

Abstract: A toothbrush is disclosed which comprises a rotatably mounted toothbrush head, 100, a connection member, 150, for connection to a linear reciprocal drive means contained in hand-held casing and a flexible member, 160, formed preferably from steel wire or ribbon disposed between the connection member, 150, and the head, 100, and for converting linear reciprocal motion of the connection member to rotational motion of the head.

Description: This invention relates to a brush for personal hygiene purposes more particularly, but not exclusively, to a toothbrush. Power driven toothbrushes, for example, electric toothbrushes, have been proposed in which either a toothbrush head or the bristles protruding therefrom are driven to move in a reciprocally rotational manner. It is a disadvantage of the such proposed toothbrushes that the transmission from a power means to the toothbrush head to drive this in reciprocal motion is generally complicated and thus expensive to manufacture. US 2598275 discloses the features of the preamble of claim 1. In this power driven toothbrush a linearly reciprocable shaft is driven by a motor, the shaft being connected off centre to a rotatable brush head. A biasing spring is used to prevent the shaft lying in a dead centre position. It is the object of the invention to provide an improved powerable brush for personal hygiene purposes. According to the invention there is provided a brush for personal hygiene purposes comprising a rotatably mounted brush head, a connection member for connection to a linear reciprocal drive means and a member disposed between the connection member and the brush head and for converting linear reciprocal motion of the connection member to rotational motion of the head, characterized in that said member disposed between the connection member and the brush head is a flexible member which is biased in a direction laterally away from the direction of linear reciprocal motion of the connection member. With an arrangement of this type, complicated gearing arrangements for converting the reciprocal motion of the connection member to rotational movement of the brush head are not needed, thus simplifying the construction of the brush. Preferably the flexible member is formed from metal wire. In a further preferred form, the flexible member is provided with a loop which is arranged to move in reciprocation with the connection member in a channel, the edges of the loop contacting the sides of the channel to support that portion of the flexible member. In a preferred embodiment the brush comprises: a main body; a detachable head part having the rotatably mounted brush head thereon; a driven member connected to the linear reciprocal drive means in said main body; and coupling means provided on said driven member and on said connection member to provide a releasable coupling therebetween, said coupling means being adapted to provide coupling between said members, when the head part is in a first orientation relative to the main body part, and to allow said members to be detached when in a second orientation in which said head part is rotated relative to the main body. By this means a simple rotation of the head part is sufficient to couple or uncouple the driven and connection member. Preferably, the main body and head part are provided with engagement means to allow these to be push-fitted together or pulled apart when the head part is in the first orientation, and when fitted, rotated to the second orientation in which the head part is prevented from release. This construction means that the coupling between driven and connection members is effected as the head part is fitted onto the main body. In a preferred embodiment, the coupling means comprise a pair of opposed legs extending from an end of the connection member having inwardly directed fingers, and a pair of grooves formed in opposite sides of the driven member within which the fingers are engagable when the head part is in the second orientation. The engagement means comprise an axial plug formed on the main body, for receipt in a socket-like end of the head part, the plug being formed with at least one outwardly directed locking lug, and the head part being formed with a lug-receiving groove having an axial portion to allow a push-fit of the head part onto the housing, and a circumferential portion defining internally a shoulder behind which the lug engages on rotation of the head part to the second orientation. One of the driven member and connecting member is formed at its coupling end with a locating pin, the other having a locating socket. The locating pin is at the end of the driven member, which narrows towards the pin, whereby the opposed legs are pushed apart as the driven member and connecting member are coupled together. Means may be provided for moving the connection member reciprocally comprising drive means for driving a cam, the cam comprising a circular member offset relative to a driving axis, the circular member being held for rotation relative to a follower connectable to the connection member via a linear guide. Rotation of the offset circular member causes a combined pivotal and linear reciprocal movement of the follower, with only the linear reciprocal component being transferred to the guide. Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which; Figure 1 is a sectioned plan view of the transmission elements of a first embodiment of the invention; Figure 2 is a sectional side view across 2'- 2' of Figure 1 showing, in addition, a brush head of the embodiment of the invention; Figure 3 is a view in the direction of arrow 3' of Figure 2 of the brush head; Figure 4 is a sectional side view of a reciprocating drive mechanism of the embodiment of the invention with Figure 5 being a view in the plane 5,- 5, of Figure 4; Figure 6 is a view similar to Figure 1 illustrating a second embodiment of the invention; Figure 7 is a view in the direction 7'- 7' of Figure 6; Figure 8 is a sectional view showing the brush head in accordance with a second embodiment of the invention; Figure 9(a) is an exterior view of a toothbrush; Figure 9(b) is a part-sectional view to show the coupling between a driven member and connection member; and Figure 10 is a detailed view showing the coupling between driven member and connection member, and between housing parts. With reference to the Figures 1-3, an embodiment of a brush, in this case a toothbrush, is shown. The toothbrush is arranged to be power driven in a rotationally reciprocal manner and comprises a head, 100, having a rotatable base member, 102, from which an array of bristles, 104, project as shown more clearly in Figures 2 and 3. The member, 102, is provided with an axially disposed bore, 106, through which a mounting pin, 108, projects. The pin, 108, is connected at one end to a support member, 110, and the head, 100, is held in place for free rotation on the pin by means of a cap, 111. The support member, 110, defines a channel in which a connection member, 150, for connection to a reciprocal driving means (shown in Figures 4 and 5) is provided. The connection member 150 is connected to member 102 of head 100 by means of a flexible member, 160, formed preferably from spring steel wire or ribbon. The flexible member, 160, is attached to the connection member, 150, by means of adhesive or a mechanical fitting and includes an upstanding free end, 162, which engages a corresponding bore, 114, which is disposed in member 102 radially outwardly of the centre. By moving the member 150 between the positions shown by full lines (112) and by phantom lines, (113) in Figure 1, the flexible member will place a torque on head, 100, thus causing this to rotate. If the member, 150, is moved reciprocally, the head will rotate backwards and forwards through an angle α, (in this case, 120°) between positions defined by the different relative positions of the end 162, that is between positions 112 and 113. The member, 160, is flexible but sufficiently rigid to rotate the head, 100, in response to force supplied from member 150, and at the same time, conform to the rotated position of opening 112. The member, 160, does not have a linear neutral position but is biased in the direction of arrow A, ie it is bent so as to exert a force in the direction of the arrow A in a direction generally perpendicular to the direction of movement. Such an arrangement acts to prevent the member, 160, when in position 112 accidentally going "over-centre" and continuing a clockwise stroke in the direction of arrow C, rather than reciprocating in an anti-clockwise direction back to position 113. The member, 110, provides a base and upstanding sides to form a channel in which member 150 reciprocates, and a cover, 170, is affixed to the sides of member 110 to encase the member, 150. The free end of member 150 is provided with means for connection to a driving member, 222, when the brush is attached to a driving means (illustrated in Figures 4 and 5). Such a driving means is preferably contained within a hand-held casing in a manner of a conventional electric toothbrush, and which will be described further below. Member 110 is connected by known means to the casing so that member 110 provides a support integral with the toothbrush casing while allowing member 150 to be driven reciprocally by the driving means. With reference to Figures 4 and 5, a driving means for the toothbrush, shown in Figures 1-3, is shown which comprises a motor, 200, to which two supporting members, 202, 204 are connected. Motor, 200, includes a shaft, 206, connected to a pinion gear, 208. A support shaft, 210, is connected between supporting members, 202, 204 and rotatably supports a driven member, 212, which includes, at one end, an annular rack, 214, for engagement with pinion, 208, and at the other, a circular member, 216, connected to the rack, 214, by a cylindrical portion, 215. The circular member, 216, is offset relative to shaft, 210, as shown more clearly in Figure 5, and is held in a corresponding opening, 218, in a follower, 220, the member 216 and follower 220 being relatively rotatable. Follower 220 is connected to a drive member, 222, by means of a pivot joint, 224. In use, rotation of motor, 200, will drive pinion gear, 208, which will in turn cause rack, 214, to rotate correspondingly, thus rotating member 212. As circular member, 216, is offset, this will follow an eccentric motion which will cause follower 220 to follow the same path of motion, thus moving pivotally about bearing 224, but also moving reciprocally in the direction of arrows B-B of Figure 5, and causing drive member 222 to follow such motion. Drive member 222 further includes first and second legs, 230, which mate against the side of the central cylindrical portion, 215, of driven member, 212, which acts to guide the member 222 on a linear path. A further embodiment of the invention is illustrated in Figures 6 and 7. Figure 6 is similar to Figure 1 with the main difference being that the flexible member (here given reference 360), includes a loop, 362, disposed between the connections to member 150 and head, 100 and resting on a shelf, 363, of member, 150. The loop, 362 has two functions. The first is that the edges of the loop are arranged to touch the sides 132, 134, of support member 110, thus steadying the flexible member as a whole. Secondly, the loop adds rigidity to the connection to the member 150, with the flexible function being provided by the portion of the member, 364, between the loop and the head, 100, which is biased in the direction of arrow A. With such an arrangement, the angle of rotation of the head can be increased to angle β (120°), to just before the path of reciprocation of the member 150. A stop, 366, is also provided which limits the movement of the connection member, 150. This allows easy engagement of the connection member with the drive member, 222, when the two are pressed together without damage to the flexible member and head. In an alternative arrangement of the head illustrated in Figure 8, a central portion of the base is provided with an upstanding disc-like portion 402 with a central pin 404. This central pin 404 is covered by a cap 406 formed of a soft resilient plastics or rubber-like material. The cap is arranged to lie a distance below the level of the bristles. This structure serves to limit the pressure with which the head is pressed against the teeth; if the user presses the head too hard against the teeth, he will feel the cap 406. This has the advantage that it reduces the chances of damage to the user's teeth and gums from the bristles, and also reduced damage and wear of the bristles, extending brush head life. Figure 9(a) shows the exterior of the entire toothbrush which has a main body 502, including a lower casing part 504 which houses a recharging unit, and fixed thereto a motor casing part 506 which houses the driving means and motor 200 described above. Detachably connected to the body 502 is the head part 508 which has the rotatable brush head 100 at its end. The head part 508 includes the member 110 and connection member 150 described above. As can be seen in Figure 10, means are provided on the main body 502 to allow releasable attachment of the brush part 508. These comprise a plug part 509 formed on the end of the casing part 506 which push-fit within a lower opening of the head part 508. The plug part 509 is formed with a pair of lugs 513 which fit in grooves 515 in the brush part. The lugs 513 and grooves 515 are relatively disposed so that after the head part 508 has been push-fitted onto the casing part 506, it must then be rotated through a quarter turn to bring these into appropriate alignment. During this rotation, the logs 513 move in internal grooves 517, engaging behind shoulder 519 so that the head part 508 cannot be pulled off the casing part 506. It is preferably arranged that the logs 513 are of different width to each other, so that the brush part can only be fitted in a single orientation. As can be seen in Figures 9(b) and 10, means are provided to allow the connection member 150 to be coupled to the driving member 222 as the head part 508 is fitted on the main body 502, and to be uncoupled on detachment of the brush part. In particular, the driving member 222 is formed with a pair of cut-outs or grooves 510, on opposite sides thereof, which define shoulders 511 at a forward end thereof. The forward or insertion end of the driving member 222 is formed with a conical portion 512 and a locating pin 514. The coupling end of the connection member 150 is formed with a pair of opposed legs 516 formed of a resilient material such as springy plastics or metal which have inwardly directed fingers 518. Formed centrally on the connection member 150 is a locating socket 520. On attachment of the head part 508, as this is pushed onto the end of the body 502, the legs 516 will become splayed apart as they move over the portion 512 and onto the regions of the driving member 222 between the grooves 510. Then, as the head part 508 is rotated, to lock this onto the body 502, the fingers 518 will engage in the groves 510 so that the members 222 and 150 are coupled for linear reciprocal motion. The locating pin and socket assist in accurate coupling. On detachment, as the head part 508 is rotated, the fingers will move apart as they move from the grooves 510 to the adjacent portion on the connection member. The head part 508 can then simply be pulled from the casing 506. It will be appreciated that because the driving member 222 is reciprocally driven, it may stop at a range of positions relative to the casing part 506 and plug 509. The position of Figure 10 corresponds to a position in which the driving member 222 is close to its forward-most position. Similarly, the connection member 150 may be at a variety of positions relative to its housing. If the driving member 222 is in an extended position, and the connection member 150 also in an extended position (away from the head), then on attachment the connection member 150 will be pushed towards the head by the member 222 (which will not move) and the head will rotate very slightly. If the driving member 222 is in a retracted position, then as the head part 508 is push-fitted on the casing part 506, the fingers 518 will not reach the region of the driving member 222 between the grooves 510. However, when the motor is activated, the fingers will then snap-fit into the grooves 510 on the first forward stroke of the driving member 222. This arrangement can thereby provide reliable coupling of the drive, irrespective of the positions of the driving member 222 and connection member 150. It will be appreciated that the locations of the coupling means could be reversed between the driven member 222 and connection member 150. Similarly, the positions of locating pin 514 and socket 520 could be reversed.

Claims: A brush for personal hygiene purposes comprising a main body and a head having a rotatably mounted brush head (100), a connection member (150) for connection to a linear reciprocal drive means, and a member (160, 360) disposed between the connection member (150) and the brush head (100) for converting linear reciprocal motion of the connection member to rotational motion of the brush head, characterized in that said member (160, 360) disposed between the connection member and the brush head is a flexible member (160, 360) which is biased in a direction laterally away from the direction of linear reciprocal motion of the connection member (150). A brush as claimed in claim 1 where in the flexible member (160, 360) is formed from metal wire. A brush as claimed in claim 1 or 2 wherein the flexible member (160, 360) is in the form of wire or ribbon. A brush as claimed in any one of claims 1 to 3 wherein the connection member reciprocates in a channel formed in a support (110). A brush as claimed in claim 4 wherein the flexible member (360) is bent to have a loop (362) therein. A brush as claimed in claim 5 wherein the loop (362) contacts sides of the channel in the support (110). A brush as claimed in any one of the preceding claims further comprising a stop (366) for limiting movement of the connection member. A brush as claimed in any one of the preceding claims wherein the brush head comprises a circular base (102) from which a plurality of bristles (104) project, the base having first means (106) for receiving a pivot and second radially offset means (112) for receiving an end of the flexible member (160, 360). A brush as claimed in any one of the preceding claims further comprising means for moving the connection member reciprocally, including drive means (200) for driving a cam, the cam comprising a circular member (216) offset relative to a driving axis, the circular member being held for rotation in a follower (220) connectable to the connection member (150). A brush as claimed in claim 9 wherein the circular member (216) is connected to an annular rack (214) engagable by a gear connected to the drive means (200). A brush as claimed in claim 9 or 10 wherein the follower (220) is connected to a linearly guided member (222) via a pivot, the linearly guided member (222) being connectable to the connection member (150). A brush as claimed in any one of the preceding claims, being a powered toothbrush. A brush as claimed in claim 8 wherein the base (102) is provided with a central upstanding protrusion (404, 406) having a free end which lies below ends of the bristles. A brush as claimed in claim 13 wherein the central upstanding protrusion is at least partly formed of a soft resilient material (406). A brush as claimed in any preceding claim comprising: a main body (502); a detachable head part (508) with the rotatably mounted brush head (100) thereon; a driven member (222) connected to the linear reciprocal drive means in said main body; and coupling means provided on said driven member (222) and on said connection member (150) to provide a releasable coupling therebetween, said coupling means being adapted to provide coupling between said members when the head part (508) is in a first orientation relative to the main body part (502), and to allow said members to be detached when in a second orientation in which said head part (508) is rotated relative to the main body (502). A brush as claimed in claim 15 wherein the main body (502) and head part (508) are provided with engagement means (509, 513, 515) to allow these to be push-fitted together or pulled apart when the head part is in the first orientation, and when fitted, rotated to the second orientation in which the head part is prevented from release. A brush as claimed in claim 15 or 16 wherein the coupling means comprises a pair of opposed legs (516) extending from an end of the connection member having inwardly directed fingers (518), and a pair of grooves (510) formed in opposite sides of the driven member (222) within which the fingers (518) are engagable when the head part is in the second orientation. A brush as claimed in claim 16 or 17 wherein the engagement means comprise an axial plug (509) formed on the main body, for receipt in a socket-like end of the head part (508), the plug being formed with at least one outwardly directed locking lug (513), and the head part being formed with a lug-receiving groove (515) having an axial portion to allow a push-fit of the head part onto the housing, and a circumferential portion (517) defining internally a shoulder behind which the lug (513) engages on rotation of the head part to the second orientation. A brush as claimed in any one of claims 15 to 18 wherein one of the driven member (222) and connection member (150) is formed at its coupling end with a locating pin (514), the other having a locating socket (520). A brush as claimed in claim 19 wherein the locating pin (514) is at the end of the driven member (222), which narrows towards the pin, whereby the opposed legs (516) are pushed apart as the driven member (222) and connection member (150) are coupled together.

Inventors: MCDOUGALL GREGORY JOHN, MCDOUGALL, GREGORY JOHN
Applicants: MCDOUGALL GREGORY J, MCDOUGALL, GREGORY JOHN
Application year: 1994
Main classification: A61C17
IPC codes: A46B13, A61C17